loop

Mathematically, a loop is a closed🔒 string with no knots or tanglements whose path initiates and terminates at the same point.

Ludologically, a loop is a simple infinite walk; such that it encloses leaves (reading frames) on a loopstring. In both cases, a loop is continuous with either no nuts, or has homologically conjoined endpoints.
/// For sake of stew choreography, a loop is just a completed walk that has become unavailable for recycling.